Re: like/ilike improvements

Tom Lane wrote:
> Andrew Dunstan <andrew@dunslane.net> writes:
>   
>> ... It turns out (according to the analysis) that the 
>> only time we actually need to use NextChar is when we are matching an 
>> "_" in a like/ilike pattern.
>>     
>
> I thought we'd determined that advancing bytewise for "%" was also risky,
> in two cases:
>
> 1. Multibyte character set that is not UTF8 (more specifically, does not
> have a guarantee that first bytes and not-first bytes are distinct)
>   

I will review - I thought we had ruled that out.

Which non-UTF8 multi-byte charset would be best to test with?

> 2. "_" immediately follows the "%".
>
>             
>   

The patch in fact calls NextChar in this case.

cheers

andrew